Fundamentals of Physics Extended (10th Edition)

Kinetic energy of the block $= \frac{Mgd}{4}$
Kinetic energy $= \frac{1}{2}Mv^{2}$ To find the expression for $v^{2}$, we use: $v^{2}=u^{2}+2ad$ $v^{2}=2\times \frac{g}{4} \times d=\frac{gd}{2}$ Plugging in respective values, we get: Kinetic energy $=\frac{1}{2}M\times \frac{gd}{2} = \frac{Mgd}{4}$